1. Field of the Invention
The present invention relates generally to support devices and more particularly to a support device for retaining a signalling device on a rail.
2. Description of the Related Art
Signalling devices are customarily used to forewarn locomotive operators of various conditions which exist on or in the vicinity of the track. Electronic signalling devices are also commonly installed at predetermined intervals to provide warning to the locomotive operator. However, such devices are costly to install and maintain. Furthermore, such signalling devices cannot warn approaching trains of temporary conditions such as speed restrictions, construction on or near the track, or hazardous track conditions.
It is well known that substantial time and distances are required to stop a locomotive or train. Furthermore, government regulations mandate the use of temporary warning devices along the track in order to inform the operating personnel of eminent unsafe or hazardous conditions. Conventional flagging devices typically include a base portion which either rests on the ground surface or is adapted to be driven into the ground along the track siding. The base is used to support a signalling flag and a flag-bearing staff or staffs. Such flagging devices are frequently installed at remote and unattended sites.
There are several defects inherent to the aforementioned flagging devices. Since railroad personnel must necessarily rely upon such temporary devices, it is of paramount importance that the device remain intact throughout the duration of its intended use. It is sometimes difficult to maintain such devices in the proper flagging position. Environmental conditions such as flooding, wildlife, landslides, etc. can easily dislodge the device. Vandals often reposition the flagging devices from their original positions. Furthermore, passing trains often generate a great deal of wind force as they travel pass flags at high speeds. Finally, they may be difficult to quickly and efficiently drive into the ground because of the surfaces upon which the track is laid.
Various attempts have been made to provide convenient and efficient signalling devices. For example, U.S. Pat. No. 269,955 issued on Jan. 2, 1883 to Paullin discloses a detonating railroad track signal. The device is designed to provide visible and audible signals that can be perceived during the day or night. A cap is provided for explosion when the wheel of the train rolls over a plunger on the track.
U.S. Pat. No. 418,155 issued on Dec. 31, 1889 to Berry discloses a railway signal which includes a signal head secured to a vertical bar. The vertical bar is subsequently driven into the ground to support the signal head.
U.S. Pat. No. 606,197 issued on Jun. 28, 1898 to Dunn discloses a railway signal for use along railway lines. The device includes a horizontal arm having one end bent in the form of a hook capable of engaging the inner flange of a track. An adjustable jaw is provided on the arm for engaging the outer flange of the track. The signal is then detachably secured to the arm.
U.S. Pat. No. 1,301,914 issued on Apr. 29, 1919 to Currie discloses a portable railway signal which includes a tubular rod having an offset near its intermediate section. A rod having and offset end is rotatably attached to the tubular rod. A movable flag is positioned on the offset end of the rod. A second rod terminating in jaws is attached to the tubular rod in order to engage the lower flange of the rail.
U.S. Pat. No. 1,320,380 issued on Nov. 4, 1919 also to Currie discloses a railway signal which includes a supporting member having its base portion passing beneath and secured to one side of a rail. The device also includes flag carrying means associated with the base member.
U.S. Pat. No. 1,371,227 issued on Mar. 15, 1921 also to Currie discloses a track signal which includes a base member having spring engaging members. The spring engaging members include turned ends adapted to engage the opposite ends of an angle plate and secure it to the rail.
U.S. Pat. No. 1,435,807 issued on Nov. 14, 1922 and U.S. Pat. No. 1,458,808 issued on Jun. 12, 1923, both to Conley disclose signal flag supports in the form of a V-shaped yoke structure adapted to be engaged behind the customary fish plate. A mast is erected at the apex end of the yoke for carrying a casing to house the signal flag.
U.S. Pat. No. 1,722,842 issued on Jul. 30, 1929 to Fahnestock discloses a signal flag holder which is resiliently mounted onto the rail. The device is adapted to be secured to the rail head and project upwardly at an angle therefrom so that the signalling member is positioned midway between the rails and in full view of a train crew in switching operations.
U.S. Pat. No. 1,747,278 issued on Feb. 18, 1930 to Zawyruchia discloses an apparatus for holding a series of flags for signals. The apparatus includes a collapsible standard and support having means in the standard for mounting a plurality of flags. Means are also provided for retaining the flags in closed or folded condition.
U.S. Pat. No. 5,038,704 issued on Aug. 13, 1991 to Dean et al. discloses a stowable temporary signalling device for rail systems. The device includes an adjustable and fixed clamping mechanism for clasping onto a rail placed therebetween for applying mechanical bias on the rail. A collapsible arm is provided to mount and support a signalling unit thereupon.
French Patent No. 394,760 published on Feb. 1, 1909, German Patent No. 248,157 published on Jun. 15, 1912, German Patent No. 268,420 published on May 4, 1913, and German Patent No. 475,030 all disclose devices for supporting railroad signs.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a track flag holder solving the aforementioned problems is desired.